Synthetic organic nonsoap detergent in bar form and process of making same



Patented Sept. 17, 1946 UNITED SYNTHETIC ORGANIC NONSOAP DETER- GENT INBAR. FORM AND PROCESS OF MAKING SAME John W. Bodman, Winchester, Mass.,assignor to Lever Brothers Company, Cambridge, Mass., a

corporation of Maine No Drawing. Application August 14, 1940, Serial No.352,519

8 Claims. 1

This application is a continuation-in-part of application Ser. No.85,985, filed June 18, 1936, which matured as Patent No. 2,215,539 onSeptember 24, 1940. Application Ser. No. 85,985 is a continuation ofapplication Ser. No. 665,063, filed April 8, 1933.

The present invention relates to an improvement in the manufacture ofdetergents and relates more particularly to the preparation of theso-called non-soap detergents" in commercially desirable forms.

The term non-soap detergents is used herein to designate materialshaving a cleaning action which are derivatives of higher fatty compoundsor compositions other than the usual soaps, i. e., soluble metal saltsof fatty acids. For convenience, I prefer to utilize the, type ofnon-soap detergents which are readily available in their relatively purform and which under normal conditions of temperature and pressure arenonliquid. Of these may be mentioned the Gardinols which are salts ofthe sulfated higher fatty alcohols, the Emco preparations which may bedescribed as sulfocarboxylic acid esters of alcohol amine derivatives,and the A-typ of the Igepon class of products which are fatty acidesters of hydroxyethane sulfonic acid. All such compositions are wellknown in the art and may be defined generically as synthetic non-soaporganic compounds having surface active properties.

In accordance with my invention, non-soap detergent compounds may beprepared in a coherent and coalescent bar or cake form which has thefine texture, firmness, shape stability and wearing qualities desirablein high grade toilet soaps. Moreover, the product may be characterizedby a desirable mildness while possessing the bulk and degree ofsolubility preferred in detergent bars or cakes.

Non-soap detergents as a class of compounds are relatively expensive andhighly soluble -in comparison with the usual soluble soaps which theyare intended to replace for cleansing and other purposes. In marketingthese compounds heretofore, it has been considered necessary to preparea product which has the bulk of an equally effective soap product and atthe same time will not be materially higher in cost. To accomplish thisresult, it has been customary to add diluents generally of an inactivecharacter, for example, of the type of sodium sulfate or sodiumchloride. Also those which have at least some of the properties of asoap builder may be added. The presence of material proportions ofinorganic electrolytes may impart to the deter- 2 gent a harsh actionwhen applied to the skin, which, obviously is undesirable in. high gradetoilet preparations.

It is now possible in accordance with my invention to prepare non-soapdetergents in bar form which can be used economically as Waste ordisintegration of the bar on use is minimized. If desired, the usualdiluents or fillers may be omitted entirely without a sacrifice of bulkand wearing qualities.

The diluents commonly used have no marked cohesive properties and whenused in any material proportlons render the detergent noncohesive anddificult of successful preparation in bar form. Attempts have been madeto neutralize at least in part this lack of cohesiveness by the use ofbinding agents. The addition of such addition agents for the purpose ofbinding together the adulterated detergent particles into bar form.however, is generally undesirable. Among the other disadvantages, forexample, of such a bar or cake, is that it will not dissolve into aclear solution. Moreover, the bar or cake is not coherent andcoalescent, being made up of individual distinct particles, and does notpossess the firmness, fine texture, and appearance desired in toiletpreparations. My invention may be utilized to produce a coherent andcoalescent bar or cake of non-soap detergent without the use of anybinding agents whatsoever.

The products of my invention may be made entirely from non-soapdetergents and with or without small amounts of diluent. If it isdesired, varying. amounts of soap may be incorporated therewith. Infact, it is found to be advantageous in many cases to combine thedesirable properties of non-soap and soap detergents. While liquid orsemi-fluid non-soap deterg nts generally may not be prepared in bar orcake form, I have found that in accordance with my invention they may beso modified that they may be eflectively used in the bar form whensuitably blended with other detergents having a normally solid form,such as a hard soap or other non-soap detergent.

In accordance with my invention the non-soap detergents may in onepreferred form be aerated, i. e., may have small amounts of a compatiblegas distributed throughout the detergent mass. If desired, the detergentmay be sufiiciently aerated to reduce its specific gravity below that ofwater, thereby producing a floating product.

The formation of the improved products of my invention may be carriedout by working the materials in admixture with small amounts of water,preferably in a closed container, at temperatures suificient to renderthe mass plastic or semi-fluid to fiuid. Under these conditions, it ispossible to manufacture a coherent bar of nonsoap detergent which may beaerated or nonaerated, floating or non-floating depending upon theconditions of processing; and one having in the preferred embodiment acharacteristically reduced solubility and tendency to disintegrate; andalso one having the properties of fine texture, continuity andappearance as well as other desirable characteristics important to theproduction of a commercially acceptable product in cake orbar form.

In producing the the new non-soap detergent bar or cake, a non-soapdetergent stock, preferably in relatively pure form and solidified inthe form of pellets, particles or fragments, is reduced to a heatedplastic or semi-fluid condition while it is intensely agitated or workedin a chamber closed to the atmosphere. The particular kind of mechanicalagitation to which the non-soap detergent mass is subjected forpreferred results should be sufiicient to move all portions of the soapmass relatively to each other and expose them equally to any source ofheat which may be utilized. The operation may be discontinued when thereresults a unitary mass of non-soap detergent suitable for passing intoform-imparting means where it may be cooled and solidified whileretaining its continuous structure. If an aerated mass is to beproduced, a compatible gas, such as air, may be introduced into the masswhile in a plastic, semi-fluid to fluid state and thoroughly distributedthrough the mass during the Working operation.

The process may be carried out in a batch type of operation or may bepracticed in a continuous manner, if desired. It is possible to use amachine of the Banbury mixer type as disclosed in the patent to Banbury,No. 1,200,070, issued October 3, 1916. A more desirable type ofapparatus for continuous operations would be the apparatus described inthe patent to Pease, No. 2,048,236, issued July 21, 1936. The apparatuswhich is selected should be adapted to thoroughly mix, shear or kneadthe non-soap detergent stock under desired conditions of temperature,moisture content, and pressure.

The temperature range under which I prefer to carry out my inventionwill depend primarily upon the type of non-soap detergent selected. Thetemperature should be sufficient to render the detergent plastic orsemi-fluid to fluid and capable of being readily worked into acoherentcoalescent body of a continuous structure in the types ofapparatus described above. For most commercially available non-soapdetergents, a temperature range of from 100 to 200 F. will besatisfactory. Temperatures above 200 F. may be used but possibly withoutachieving the full benefits of my invention in its preferred form, forwith some non-soap detergents it has been found that when excessivelyhigh temperatures are used, the resulting detergent product will besubjected to generally undesirable shrinkage in bar form during cooling,although in other respects the results may be satisfactory. Temperaturesbelow 100 F. may be utilized with some non-soap detergents, provided thedesired degree of plasticity is obtained. In using liquid or semiliquidnon-soap detergents with solid detergents the temperatures used shouldbe sufficient to make plastic or otherwise modify the solid detergent tothe most desirable form. The temperature should permit uniform blendingand a continuity of the mass in the final product.

The method utilized for obtaining the desired temperature conditions isnot critical. For convenience, the non-soap detergent stock, forexample, in particle form, may be preheated in part or in whole to thedesired temperature prior to charging it into the mixing apparatus, orheat may be applied to the detergent while it is in the mixer, eitherduring or before agitation, in any convenient manner.

The processing of the non-soap detergents may be carried out at amoisture content varying over a wide range and depending primarily uponthe type of non-soap detergent selected for processing. In most cases, amoisture content of from 10-20% will be satisfactory. A moisture contentof less than 10% may be utilized with most nonsoap detergents, ifdesired, but in general lower percentages of moisture render thematerial difiicult to plasticize, at least in the types 01' apparatuswhich are available at present. When a moisture content of approximately20% is exceeded, the product in most cases tends to have a rather softand sticky form. The upper moisture limit, however, will varyconsiderably, depending upon the type of non-soap detergent selected.For example, it has been found that the Emco products referred tohereinbefore may be formed into a firm bar with a moisture content ashigh as 35% if used alone. If blended with other detergents that wouldbe made undesirably liquid or sticky by high proportions of water orhigh temperatures, a lower average water content would be more suitable.

For convenience, I prefer to utilize as a starting material thosenon-soap detergents prepared commercially with a moisture content withinthe limits set forth above; if necessary, however, the moisture contentmay be regulated prior or during processing in any suitable manner knownto the art.

With a view to obtaining preferred characteristics in the product, it isdesirable to subject the non-soap detergent mass to pressure whileworking. This insures an effective working action and minimizes theescape of moisture and air from the mass. It is desirable to have theair distributed in a fine uniform condition and it is believed that theuse of pressure increases the desirable air distribution. The pressuremay cause the air to be dissolved in the plastic or semi-fluid mass. Theair is then released in a highly dispersed form throughout the mass uponrelease of pressure upon the mass. Any convenient pressure beginning atslightly over atmospheric to pounds per square inch or more may be used.Pressures of 25 pounds per square inch have been found suitable. Thepressure is preferably increased when higher temperatures are employed.

In carrying out my invention, it is desirable to use non-soap detergentswhich are available commercially in a relatively pure state or which maybe readily purified. In addition to having a milder action on the skin,it has been found that the absence of inorganic salts increases thefirmness and fine texture of the resulting product. However, smallpercentages of inorganic material, for example, up to 15%, may bepresent in the detergent product without undesirable effects.

If desired, varying percentages of ordinary soaps may be incorporatedwith the non-soap detergents. These materials may be mixed in allProportions and for many purposes as high as 7 to 80% of soap may beused. When material percentages of soap are incorporated it generally isdesirable to modify and blend the non-soap detergent with the soap byworking as described, utilizing preferably temperatures of more than 145F. and with a moisture content of the soap of less than 25%. I havefound that by blending as described a non-soap and soap detergent aproduct may be produced having particularly desirable properties. Thedetergent effectiveness is materially increased in hard water districtsand in sea water and any tendency for the more soluble non-soapdetergent incorporated to leach out or separate is minimized in view ofmy processing. In its preferred form this product is aerated duringprocessing, sufficiently to float.

For convenience, the non-soap detergent stock to be used in carrying outmy invention may be in the form of the usual commercial spray-driedproduct. When the operation is carried out in a continuous fashion thecharging of the spraydried non-soap detergent into the apparatus isusually accompanied by the inclusion of sumcient air to insure anaerated or even a floating product. If a compacted charge is used, itmay be necessary to supply an additional quantity of air to theapparatus. When operating under a batch system, sufficient air may bemade available for incorporation by only partly filling the machine.

Agitation of the non-soap mass preferably with heating and underpressure may be continued for a sufficient period of time to disseminatethe air in a finely-divided condition throughout the entire mass and toplasticize the mass as a continuous and coherent body. When the mass iscompletely mixed, it may be released or discharged by extrusion underpressure or otherwise into a mold or form-imparting means. If desiredthe pressure may not be released until in the form-imparting means. Thedetergent cools and solidifies in a desired coherent and coalescent formand may be reduced to any desired shape by cutting or trimming andimpressed with a design by a stamp or die.

The following examples serve to illustrate the manufacture of asatisfactory coherent floating bar from non-soap detergents.

Example I Per cent Sodium salt of lauryl sulfate 81 Inactive diluent 9Water 10 This mixture was Worked vigorously at a temperature of 200 F.and then extruded into a mold and cooled. The resulting bar had aspecific gravity of 0.88.

Example II Per cent Non-soap detergent (sulfocarboxylic acid ester ofalcoholamine derivative) 59.5 Potassium chloride 7 Potassium sulfate 3.5Water 30 The non-soap detergent was composed of sulfocarboxylic acidesters of mono-ethanolamine. This mixture was Worked at a temperature of160 F. The resulting bar had a specific gravity of 0.83.

Example III Per cent Non-soap detergent (sulfocarboxylic acid ester ofalcoholamine derivative) 8.5 Potassium chloride 1 Potassium sulfate Soap(20 coconut oil, tallow) anhydrous Water The non-soap detergent utilizedin the above example was composed of sulfocarboxylic acid esters ofmono-ethanolamine. When processed at a temperature of F., this mixtureproduced a floating bar of good'texture.

Soap (20 coconut oil, 80 tallow) anhydrous 77 Water 18 The non-soapdetergent used in this example was an alkyl aryl sulfonate. Whenprocessed at a temperature of 200 F., this mixture produced a floatingbar.

In accordance with the disclosure herein it will be seen that a bar orcake may be prepared in accordance with my invention which will wearsufficiently slowly to make its use economical when compared todetergent products made from ordinary soaps or from non-soaps with highproportions of fillers. The bar has the texture and appearance desirablein a high grade toilet soap and is satisfactory in every respect forordinary usage. In addition it may be aerated sufficiently to float thushaving, in addition to the advantages of a fine toilet soap, the wellknown desirable properties of a floating soap.

It is to be observed that the amount of inert material present in anexample of a preferred product is a relatively small amount, forexample, less than 15%. Despite the presence of only a small amount ofinert filler or its complete absence the non-soap detergent product inbar form is not wastefully given off during ordinary usage. Because ofthis increased coherency of the mass as a result of the utilization ofmy process it is possible to make a coalescent bar consisting entirelyor in part of non-soap detergent material without the disadvantage ofusing binders.

Apparently the processing as described tends V to decrease thesolubility or disintegration of the mass sufficiently to release uponuse, and without waste, only about that amount of deter-gent desired ornecessary for a detergent effect. A preferred bar or cake results havinga continuous body free from laminations or cleavage planes.

The aeration of the mass is also an important factor in the productionof a preferred form of non-soap detergent bar for by aeration the bulkof the relatively expensive ingredient is materially increased and itssolubility decreased. The type of aeration is probably an importantfactor in obtaining these results in a maximum amount. The bestembodiment, I have found, results from aerating the mass while workingin a plastic or semi-liquid heated condition under pressure. The productso formed is characterized by an extremely fine air distributionimparting a white color and smooth feel. A material proportion of theair cells in some masses so processed have been found to be highlyirregular in shape and constitute no more than tiny fissures betweencrystals.

It will be apparent that my invention is susceptible to many variationsand all uch varia- 7 tions are intended to be included in the scope ofthe following claims.

I claim:

1. A process for making a coherent and coalescent bar of a normallynon-liquid synthetic organic non-soap detergent compound having surfaceactive properties, said bar having an aerated continuous mass of finetexture and firmness comprising subjecting a mass of a normallynonliquid synthetic organic non-soap detergent compound having surfaceactive properties having a moisture content of less than about 35% to aU temperature of the order of 100 to 200 F., working the mass in thepresence of a compatible gas under pressure, and thereafter forming themass into bars or cakes.

2. A process for making a coherent and coalescent bar of a normallynon-liquid synthetic organic non-soap detergent compound having surfaceactive properties, said bar having an aerated continuous mass of finetexture and firmness comprising subjecting a mass of a normallynon-liquid synthetic organic non-soap detergent compound having surfaceactive properties having a moisture content of leSs than about 35% to atemperature at which the mass is semi-fluid to fluid and continuous,aerating the continuous mass under pressure while working, andthereafter forming the mass into bars or cakes.

3. A process for making a coherent and coalescent bar of a normallynon-liquid synthetic organic non-soap detergent compound having surfaceactive properties, said bar having good wearing qualities and containingless than of diluent material, which comprises subjecting a mass of anormally non-liquid synthetic organic non-soap detergentcompound of atleast 85% purity having surface active properties, to a temperature atwhich the mass is semi-fluid to fluid and continuous, aerating thecontinuous mass under pressure while working and thereafter forming themass into bars or cakes.

4. A process for making a coherent and coalescent bar of a syntheticorganic non-soap detergent compound having surface active properties andan alkali metal soap, said bar having an aerated continuous mass of finetexture and firmness which comprises subjecting a mass comprising morethan about 4% of said non-soap detergent compound and not more than 80%of said alkali metal soap to a temperature at which the said mass issemi-fluid to fluid and continuous, aerating with working said semifluidto fluid and continuous mass in the presence of a compatible gas underpressure and solidifying and forming the said aerated mass into bars orcakes.

5. The process of producing a floating bar from a mass of a majorproportion of alkali metal soap and a minor proportion of a syntheticorganic non-soap detergent compound having surface active properties,said bar having fine texture, firmness and a continuous aerated mass,said process comprising subjecting said mass in a closed chamber underpressure to intensive agitation while at a temperature whereby the massis in a plastic or semi-fluid condition and in the presence of air andforming the continuous aerated mass into a firm bar having a finetexture and a continuous aerated mass.

6. An aerated cake or bar suitable for detergent purposes comprising anormally non-liquid synthetic organic non-soap detergent compound havingsurface active properties having a continuous aerated mass of finetexture and firmnes-s, said aerated mass resulting from the cooling of asemi-fluid to fluid and continuous normally non-liquid synthetic organicnon-soap detergent mass through which a compatible gas has beendisseminated while Working under pressure and at a temperaturesuflicient to render said non-soap mass at least semi-fluid andcontinuous.

7. A process for making a coherent and coalescent bar of a syntheticorganic non-soap detergent compound having surface active properties andan alkali metal soap, said bar having an aerated continuous mass of finetexture and firmness which comprises subjecting a mass comprising notmorethan of soap with a moisture content of less than 25% and more thanabout 4% of said non-soap detergent to a temperature of more than F.,aerating while working the mass under pressure in the presence of acompatible gas and forming the said aerated mass in bars or cakes.

8. A floating aerated cake or bar suitable for detergent purposescomprising a synthetic organic non-soap detergent compound havingsurface active properties in an amount of more than about 4% and analkali metal soap in an amount of not more than about 80%, said cake orbar having a continuous and uniformly aerated mass, said aerated massresultingfrom the cooling of a semi-fluid to fluid and continuoussynthetic organic non-soap detergent compound having surface activeproperties in an amount of more than about 4% and an alkali metal soapin an amount of not more than about 80%, through which a compatible gashas been disseminated while working under pressure and at a temperaturesufiicient to render said non-soap mass at least semi-fluid andcontinuous.

JOHN W. BODMAN.

